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The viruses within the site have all been made safe to trial

Disk destroyer

His personal favourite is a virus called Casino, which overwrote a crucial part of the computer's file system but took a copy of personal files and then offered the user the opportunity to win them back in a game of Jackpot.

"Casino was a real problem," Mr Hypponen, who works at security firm F-Secure, told the BBC.

"At the time the advice was, you lose nothing by playing. In the early 1990s very few people had back-ups so you had lost your files anyway."

He said he was surprised by the number of people who felt nostalgic about the old malware.

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The Casino virus was a precursor to today's ransomware

"Most of the malware we analyse today is coming from organised criminal groups... and intelligence agencies," Mr Hyponnen added.

"Old school happy hackers who used to write viruses for fun are nowhere to be seen."